Apparatus for curing of tobacco



D@@a 119 31959 J. B; MOORE, JR 2,34,618

APPARATUS FOR CURING OF TOBACCO Original Filed Jan. 23, 1945 3 Sheets-Sheet 1 Dmo 11.9 1950 J. B. MOORE, JR

APPARATUS FOR CURING 0F TOBACCO Original Filed Jan. 23, 1945 5 Sheets -Shee't 2 ATTOR Y Dec, 119, 1950 J. B. MOORE, JR

APPARATUS FOR CURING 0F TOBACCO Original Filed Jan. 23, 1945 3 Sheets-Sheet 3 Patented Dec. 19, 1950 aster APPARATUS FOR CURING F TOBACCO James B. Moore, Jr., Lexington, Ky.

Original application January 23, 1945, Serial No. 574,078. Divided and this application October 28, 1946, Serial No. 706,242

6 Claims.

The present invention relates to an apparatus for the curing of tobacco leaves, and more particularly to an apparatus especially suitable for the curing of tobacco leaves known as brightleaf flue-cured tobacco.

In U. S. application, Serial No. 574,078, filed January 23, 19 45, now U. S. Patent No. 2,475,568, there is disclosed a method for curing brightleaf tobacco, and this application is a division of the aforesaid prior application.

In the curing of tobacco, and particularly brightleaf flue-cured tobacco, it is necessary to maintain conditions during the yellowing, drying and killing out of the tobacco stems Within carefully controlled ranges, and in the prior application referred to a process is set forth wherein these steps are efiected in the shortest possible time and under carefully controlled humidity and air circulation conditions.

It is one of the objects of the present inven tion to provide a novel apparatus which is es-- ecially suitable for yellowing, drying and killing out of bright-leaf flue-cured tobacco.

A second object of the present invention is to provide a novel apparatus including an enclosure provided with means for supporting a plurality of tobacco leaves, and means for supplying a carefully controlled current of air to the leaves supported within the enclosure.

A third object of the present invention is to provide a tobacco curing barn or the like with suitable conduits Within the upper portion of said barn, said conduits supplying a controlled urrent of air to tobacco leaves which are suitbly supported within the learn, together with ;-ieans to exhaust air from the lower portion of he barn, a return duct from the lower porion of the barn to a suitable conditioning and/ or 'ieating apparatus.

A fourth object of the present invention is to provide a tobacco curing apparatus having an enclosure provided with means to support a plurality of tobacco leaves, means to supply air to the upper portion of said enclosure from a plurality of conduits or the like, means to exhaust air from lower part of the enclosure, and means to return at least a portion of said air to an air conditioning and/or heating apparatus outside or" the enclosure, the air conditioning apparatus being controlled by a suitable temperature regulator subject to conditions within the enclosure.

Other objects and advantages of the present invention will become apparent from the subsequent description and figures of the drawing wherein:

Figure l is a transverse section more or less diagrammatic of an apparatus for carrying out the present invention;

Fig. 2 is a plan view of the tobacco barn;

Fig. 3 is a cross section taken on the line 3-3 of Fig. 1;

Fig. 4 is a transverse section of a modified form of apparatus;

Fig. 5 is a section taken on the line 5--5 of Fi 4.

Referring to the drawing, IE3 represents a tobacco barn in which tobacco leaves it are hung, the latter being tied on sticks, the sticks of tobacco being supported on tier rails 12. The barn it is provided with an exit duct [3 and a return air duct it, the former being provided with a:

pressure damper Be. The return air duct Et is also equipped with a regulating damper l6 and the return air duct has an opening ll with a slide cover I B by which means fresh air can be admitted to the duct and to the system. A pressure blower is is operatively connected to the duct M, said blower being equipped with an electrical or gasoline motor 28. The blower is operatively connected to the base of the jacket 22 of the furnace 23, the latter being equipped with a vaporizing oil burner means 24 which is connected to the heat exchanger 25 provided with a flue pipe 26 passing through the roof of the shed 2i. Operatively connected to the bonnet of the furnace is a supply duct 28 provided with a limit control 29, said control functioning to cut off and on the oil burner at a predetermined temperature, usually within a range of to 200 F. The duct 28 passes into the barn 18, preferably centrally thereof, at the point 282) and is connected by means or" a duct 28a to an auxiliary distributing duct 38 provided with a splitter damper 3 i. The auxiliary supply ductis operatively connected to distributing ducts 32 and 33 respectively, said ducts being of any appropriate shape but preferably triangular, and the sides thereof are provided with staggered apertures 3 whereby air is introduced into the barn and distributed even- 1y over the tobacco leaves therein. Suitably disposed outside of the tight barn ill is the remote bulb thermostatic temperature control 35, preferably having a range from about 80 to F. and provided with a thermostatic element 35' extending into the barn and subject to the temperature therein.

The oil burner is provided with an automaticflowmetering valve 86 which is connected by means of a pipe 31 to the oil tank 38. The

- thermostat 35 controls the oil and on magnetic valve of the flow control valve 36. The temperature control 35 is capable of being set to turn on the burner valve 36 so as to maintain any predetermined temperature range within the barn I0.

The following is a specific example illustrating the present invention:

The barn l which is gas tight is filled with about 6,000 pounds of tobacco, the amount which can be introduced into a barn which is 16 x 16 X 16. The tobacco leaves are leaves which have been primed from the tobacco stalks and tied onto sticks, said sticks being hung over tier rails until the barn is filled. The field ripened tobacco is introduced into the barn I0 as quickly as possible after the priming. The object of introducing the tobacco leaves into the barn [0 as soon as possible after the priming is to prevent deterioration of the tobacco. It may be stated that tobacco of the character being treated by the present invention is rather perishable, it being well-known that if the tobacco is left in the fields and subjected to sunlight for a period of a days time, it will materially depreciate in value. It is therefore desirable, in order to preserve the high quality of the tobacco, that the tobacco be introduced into the barn as soon as practicable.

It is quite desirable that the process of yellowing, drying and killing the tobacco be started as soon as practicable after the tobacco leaves have been introduced into the barn l0. However, if the tobacco in the barn is kept dark and away from sunlight no appreciable harm will result in 24 to 36 hours. However, as stated, it is the preferred procedure that after the barn is filled with about 6,000 pounds of field ripened tobacco leaves, to initiate the treatment of the tobacco leaves in accordance with the present invention, it may be stated that the field ripened tobacco contains between '80% to 88% of moisture and one of the objects of the present invention is to complete the ripening of the tobacco and then to dry the tobacco to substantially remove the moisture content without damaging the quality of the tobacco.

After the tobacco leaves have been introduced into the barn [0, the damper l on the exit duct [3 is closed and the slide cover l8 on the return duct 10 is pushed forward to about one inch of the edge of the opening 1'! so as to allow a small amount of fresh air to be admitted to the return duct 14. Damper I6 is placed in its full open position to allow free access of return air from the barn I 3 to the return air duct E4. The belt connecting blower l9 and the motor is then adapted on operation to deliver about 1,500 C. F. M. of air composed of 100 cubic feet of fresh air and 1,400 cubic feet of return air to the furnace The small amount of outside fresh air functions to l eep the relative humidity of the circulated air from reaching the dew point where, as is well-known, condensation occurs. If condensation forms on the tobacco leaves, the latter become oxidized and assume what is known in the art as a spongy state. As stated, the function of the fresh air is to keep the recirculated air from reaching the dew point and therefore, functionally stated, enough outside fresh air should be introduced or combined with the recirculated air to maintain the relative humidity of the mixture below the dew point. It is therefore recognized that the amount of fresh air introduced at this point may be somewhat varied and still come within the spirit of the present invention.

After the dampers and valves have been adjusted as above set forth, the thermostat set to 90 to 95 F. or 100 F., and the limit control 29 set at approximately 130, then the burner 23 is started, the blower [9 having been placed in operation. The mixture of air produced as above set forth then begins to circulate through the barn l0.

It is desired to point out that the relative humidity of the recirculated air is maintained within a range which will allow the tobacco leaves to yellow without any substantial drying. In accordance with the present invention it is found that the most satisfactory results are obtained during the yellowing period when the recirculated air is maintained with a relative humidity of 95 to 98%. Less satisfactory results are obtained when the humidity is maintained between 90 to 95%. It is therefore desired not to limit the invention to a range of humidity during yellowing of 95 to 98%.

When processing a batch of 5,000 pounds of tobacco it has been found that operating with the above quantity of air and under the above conditions of humidity, the tobacco is yellowed in a period ranging from about 36 to 60 hours. Naturally, this period will vary somewhat depending on the physical and chemical characteristics of the tobacco, the size of the tobacco leaves, and their state of field ripeness. If the tobacco leaves are thick and the stems are large and only partially ripened, the time of yellowing under the conditions set forth will approximate the period of 60 hours. If the tobacco leaves are thinner and the stems are smaller, the time of yellowing under the conditions above set forth may be decreased to about hours. Tobacco leaves have been satisfactorily yellowed using the present invention when treated under the conditions set forth for a period of 36 and 40 hours, respectively. Depending on the above circumstances the time of yellowing under the conditions set forth may vary from 36 to 48 hours, 36 to hours, or 36 to hours.

It is desired to point out that for a burner of the size set forth and operating under the conditions set forth that there is substantially complete recirculation of air in the barn every 2 to 3 minutes. This rate of air movement through the barn will be the same regardless of the size of the barn used for curing the tobacco leaves. The rate of flow of the air introduced into the barn during the yellowing period should be increased so that the air is recirculated at the rate above set forth, that is, a complete recirculation of all the air in the barn occurs every 2%; to 3 minutes. Using a barn 20 x 20 x 16, and having a volume of 6,400 cubic feet, the amount of cubic feet of air circulated through the barn would be increased to 2,100. During a three-minute cycle air would be recirculated at the rate of 5,295 cubic feet of recirculated air and 375 cubic feet fresh air, making a total of 6,400 cubic feet for the three-minute cycle. Using the 16 x 16 x 16 barn for a threeminute period the total amount of air circulated would be 4,500 cubic feet of which 500 cubic feet would be fresh air and 4,200 cubic feet recirculated air.

When the tobacco leaves reach their desired yellow color as indicated by visual inspection, the yellowing step is terminated and the drying step is initiated by first setting the thermostat 35 to about F. to F. or F. Thereafter the damper [5 in the exhaust duct I3 is placed in its full open position, the return air damper I6 is placed in its full open position, and the belt connecting the motor and fan is placed in its maximum position for the full operation of the blower. Air is drawn in through the opening I! into the return air duct i4 and is forced by the blower l9 through the duct 28, preferably at the rate of 4,000 C. F. M. From the duct 28 the air traveling at the rate set forth is introduced into the barn l0, preferably for a period varying between 24 to 48 hours. The air functions to dry the tobacco leaves and the temperature of the tobacco will gradually increase during the time period set forth from F. to about F. or F. It is desired to point out that by maintaining this lower temperature and increasing the air flowacross the tobacco the rate of drying is increased without damaging the cell structure of the tobacco and, the

volatile oils of the tobacco are retained. Therefore, while 120 F. or 130 F. has been set forth as the maximum or preferred temperature during the drying period, it is recognized that even using the exceedingly high rate of 4,000 cubic feet of fresh air per minute that the temperature of drying may be increased to 130 F., F., or even F. Experiments have been carried out using a drying temperature as high as or F. but the best and most satisfactory results are obtained when using a drying r;

temperature of 120 F. to 130 F. If the temperature is increased over about 120 F. or 130 F., with each increase there is usually a deteriorating change in the quality of the tobacco until complete facing occurs which seals the cell structure so that moisture on the inside of the leaf cannot be removed. This is highly undesirable.

During the drying period the humidity of the air leaving the exit duct I3 will change from approximately 93% relative humidity at the initiation of the drying period to approximately 25% to 30% and substantially all of the moisture has been taken out of the tobacco leaves, but a considerable amount of moisture still is left in the tobacco stems. The amount of moisture present in the leaves will depend upon the particular kind of tobacco being treated and its growing history,

During the drying period the air in the barn is changed approximately every minute, this having given the most satisfactory results. The general statement as to the frequency of change is that the air may be changed in the barn l0 during a period ranging in length from 45 seconds to about 1, 1% or 2 minutes. The rate of drying may be increased to approximately onehalf minute air change but care would have to be exercised to inhibit facing of the tobacco. It should be borne in mind that the rate of evaporation of the moisture from the tobacco leaves should be governed by the total amount of heat being introduced into them and if this rate is accelerated beyond a certain point the cell structure would be damaged and facing would occur.

After the tobacco leaves have been properly dried it is necessary to dry the tobacco stems and this stage is technically known as the killing out stage. At the end of the leaf-drying period, the damper I 5 and exit duct [3 are practically closed, that is, only a small opening remains sufficient to bleed off the excess air from the barn. The damper [6 in the return air duct [4 is then placed in its full open position and the slide damper I8 is practically closed to within one or two inches of its full shut position. This will allow a small quantity of fresh air to enter the return air duct 14 and be mixed with the recirculated air from the barn l0. At approximately the same time the thermostat 35 is set to about 150 F. to 190 F. The limit control 29 is then set in its full open position and preferably at 250 F. During the killing out period the object is to gradually increase the temperature of the tobacco and of the air circulating in the barn to that point which is sufficient to remove the remaining moisture in the tobacco stems, preferably the tobacco temperature and that of the circulating air is allowed to reach about 150 F., but may be as high as F. or F. After the moisture has been removed from the tobacco leaves during the drying period, the increase in temperature will not have any deleterious effect upon the properties or the quality of the dried tobacco leaves. During the killing out period, the air is circulated at approximately the same rate as used during the drying period, it being pointed out, however, that during the drying period all fresh air is used and that during the killing out period only about 10% fresh air is introduced into the barn. In other words, at any given period of time the circulating air in the barn comprises 90% of old recirculated air and 10% of fresh air. During the killing out period a small portion of the total contents circulated through the barn I ii'is exhausted through the exhaust duct 13 and to compensate for this loss of air, a small amount of fresh air is let into the barn to keep the circulated air from building up to a high humidity. Usually it is best to maintain the relative humidity of the air circulating in the barn in during the killing out period as low as possible and generally within a range of 10% to 15%. At the initiation of the killing out period the humidity of the circulating air will probably be in the neighborhood of 20%, 25% or 30%.

The killing out period will usually range from 24 to 48 hours depending upon the physical and chemical characteristics of the tobacco and depending on the thickness of the stems. It is preferred that during the killing out period that there be a complete air recirculation every minute although here again this may be reduced to one-half minutes or may be increased to 1 1 1%, or 2 minutes. The total amount of air circulated per minute through a barn 16' x 16' x 16 is 4,000 cubic feet, of which approximately 7%; to 15, but preferably 10% is fresh air.

It is desired to point out that the tobacco stems should be substantially completely dried so that when the tobacco is exposed to the unconditioned air it will not readily absorb moisture and in doing so produce what is known as swell stems. Generally, the moisture content should be reduced as low as possible and it usually varies between 3% to 8%, but it is most desirable to reduce the moisture content to about 5%.

The temperatures during the killing out period are well below the kindling point of the tobacco thereby alleviating any possibility of fire.

The present invention provides a process for the curing of tobacco that is reasonably controllable, is economical from the standpoint of manpower use and produces a more uniform product with a slight increase of the weight of the finished product. 1

The present invention substantially decreases the fire hazard as there are no'direct radiating 1 surfaces within the barn which could cause at any time a temperature near the kindling point of tobacco.

It is well-known that during the yellowing period the tobacco gives off a gas including ethylene gas and if this gas is allowed to become too highly concentrated at any portion of the barn or other treatment container, it will over-ripen the tobacco leaves. Heretofore it has been necessary during the yellowing period to keep the relative humidity of the treatment gas or .air to around to in order to prevent the ethylene gas from damaging the tobacco. In prior practice, when the air in the barn containing the sticks of tobacco became stagnant, then the barn was heated and the current of air was generated, said current moving the ethylene gas out of the barn and allowing fresh air to enter the barn. When this was done the relative humidity was lowered as a result of the introduction of fresh air into the barn. Because in the present process the air in the barn is not allowed to become stagnant and a small quantity of fresh air is introduced at all times, the concentration of ethylene gas present per cubic feet of air is kept exceedingly low. Because of the absence of stratified layers of ethylene gas which would over-ripen the tobacco in localized areas, it is not necessary to introduce a large amount of fresh air bringing the concentration of ethylene gas too low to function usefully as a ripening agent, and further, it is possible to operate at a humidity of to 98%, and preferably to 98%. If the relative humidity of the circulating air in the old process of ripening and yellowing tobacco were raised to 95% to 98%, then the tobacco leaves would be come over ripened, that is, sections of a particular leaf would have brown spots indicating overripening.

Practically all of the curing barns now in use are provided with a ventilator and this has been shown in the drawings. However, in accordance with the present invention the barn is airtight and therefore the barns now in use are made airtight by sealing off the ventilator by means of a sealing panel 39 which may be made of any desirable materials such as plywood, wallboard, or wooden boards.

In accordance with the present invention the yellowing of the tobacco is carried out by subjecting the tobacco to treatment with a circulating current of air preferably having a temperature varying between 90 F. and 100 F., and a relative humidity of the character herein set forth, but most desirably varying from about 95% to 98%. Thereafter the tobacco is dried by subjecting it to a'current of air which may vary from F. to 160 F. but preferably not higher than or F. The tobacco stems are then subjected to a killing out period by treating the tobacco with a circulating current of air having a temperature varying between about 140 F. to about 170 F.

In the best form of the invention the tobacco is yellowed by subjecting it to a circulating current of air for a period of time varying from about 36 to 60 hours, said air being heated to a temperature which inhibits any substantial drying of the tobacco leaves, the circulated current of air having a relative humidity of above about 90% to 92%, and below but adjacent the dew point, that it, somewhat below 100% saturation, the dew point bein taken as 100%. If the air has a humidity of 98%, 98.5% or 97%, it is then below but adjacent the dew point within the terminology herein used. The current during the yellowing period comprises a predominating quantity of recirculated air and a small quantity of fresh air which keeps the composite circulating air-medium below the dew point. Thereafter the yellowed tobacco is dried for a period of time varying from about 24, or in some cases 20 hours to about 48 hours while gradually increasing the temperature of the tobacco to about 130 F. The tobacco is simultaneously subjected to a current of circulating fresh air, the relative humidity of which at the outlet of the curing chamber is gradually reduced from adjacent the dew point to a relatively dry state. The so-treated tobacco is then subjected to a current of heated air for the killing out period varying from about 20, or 24 hours to about 48 hours while gradually increasing the temperature of the tobacco from the temperature durin the drying period about 170 F. and preferably about F. The heated air during the killing out period decreases in relative humidity and is rel atively dry at the end of the killing out period.

Referring to the modified form of the invention shown in Fig. 4; the barn i0 is shown provided with a modified type of outlet duct 20, this duct having only a single outlet. The oil heater 23 is provided with a pair of stacks indicated at and 62 respectively. The outlet duct or stack 42 is carried up through the supply duct 28, and the outlet duct Gil. The heat of the flue gases coming from the furnace 23 will therefore be conducted to the drying air which is passing through the supply duct 28. A pair of dampers 43 and 44 are provided within the conduits 42 and 41 respectively, and if it is desired to out Oh the fiow of hot flue gas from the conduit 42, the damper 43 is closed and the damper 44 is opened. This mode of operation may be especially desirable during certain phases of the yellowing operation when a relatively high humidity and low heat is maintained.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In an apparatus for the curing of tobacco, a substantially air-tight curing chamber, means for suspending therein sticks of tobacco, means for introducing heated air therein, a pair of opposed outlets extending from the lower portion of said chamber, damper means in said outlets whereby the outlets may be selectively connected to the chamber, a furnace including a heat exchange jacket, a conduit connecting one of said outlets to'the heat exchange jacket, blower means in said conduit, an inlet port in said conduit, means to open and close said port to selectively admit air to said conduit, said means for introducing heated air into the curing chamber including an inlet supply conduit delivering heated air to said chamber and an outlet conduit for exhaust gas connected to said furnace and extending through the supply inlet conduit for substantially the entire length of said conduit, said supply conduit for the heated air being partially disposed in the upper portion of said curing chamber and provided with a plurality of apertures for evenly distributing the heated air over the tobacco leaves.

2 In an apparatus for the curing of tobacco, a substantially air-tight curing chamber, means for suspending therein sticks of tobacco, means for introducing heated air therein, a pair of opposed outlets extending from the lower portion of said chamber, damper means in said outlets whereby the outlets may be selectively connected to the chamber, a furnace including a heat exchange jacket, a conduit connecting one of said outlets to the heat exchange jacket, blower means in said conduit, an inlet port in said conduit, means to open and close said port to selectively admit air to said conduit, said means for introducing heated air into the curing chamber including an inlet supply conduit delivering heated air to said chamber, said supply conduit being partially disposed in the upper portion of said chamber, and an outlet conduit for exhaust gases connected to said furnace and extending through the supply inlet conduit for substantially the entire length of said conduit, a second outlet conduit extending from said furnace for exhausting gas, and control means for directing the exhaust gas from the furnace selectively through either of said outlet conduits.

3. In a tobacco-curing apparatus of the class described, the combination of a substantially air-tight curing chamber, means in said chamber for suspending sticks of tobacco, heating means disposed outside said chamber at one side thereof and adapted to force heated air thereinto, an air-suppl duct having one end portion thereof operatively connected to said heating means and its main body portion extending upwardly therefrom within said chamber and then transversely of the latter substantially the entire length thereof with its opposite end terminatin relatively short of the inner wall of that side of said chamber which is opposite said heating means, an outlet conduit disposed within said duct and having its outer periphery spaced from the inner periphery of said duct, said conduit having one end portion also operatively connected to said heating means and its opposite end portion extending outwardl through said side of the curing chamber which is opposite said heating means, and means for controlling the passage of gases through said conduit.

4. In a tobacco-curing apparatus of the class described, the combination of a substantially airtight curing chamber, means in said chamber for suspending sticks of tobacco, heating means disposed outside said chamber at one side thereof and adapted to force heated air thereinto, an airsupply duct having one end portion thereof operatively connected to said heating means and its main body portion extending upwardly therefrom within said chamber and then transversely of the latter substantially the entire length thereof with its opposite end terminating relatively short of the inner wall of that side of said chamber which is opposite said heating means, an outlet conduit disposed within said duct and having its outer periphery spaced from the inner peripher of said duct, said conduit having one end portion also operatively connected to said heating means and its opposite end portion extending outwardly through said side of the curing chamber which is opposite said heating means, an exhaust pipe extending outwardly from said chamber independently of either said duct or conduit, and means for controlling the passage of gases through said conduit and flue pipe.

5. In a tobacco-curing apparatus of the class described, the combination of a substantiall airtight curing chamber, means in said chamber for curing sticks of tobacco, heating means disposed outside said chamber at one side thereof and adapted to force heated air thereinto, a pair of oppositely-disposed outlets extending from said lower portion of said chamber, an air-supply duct having one end portion operatively connected to said heating means and its main body portion extending upwardl therefrom within said chamber and then transversely thereof substantially the entire length thereof with its other end portion terminating relatively short of the inner wall of that side of said chamber which is opposite said heating means, an outlet conduit disposed within said duct and being of less diameter than the same so as to provide a space therebetween, said conduit having one end portion also operatively connected to said heating means and its opposite end portion extending outwardly through said opposite side of the curing chamber, an exhaust pipe extending outwardly from said chamber independently of either said duct or conduit, and thermostatic control means disposed within said conduit for controlling the temperature therein.

6. In a tobacco-curing apparatus of the class described, the combination of a substantially airtight curing chamber, means in said chamber for suspending sticks of tobacco, heating means disposed outside said chamber at one side thereof and adapted to force heated air thereinto, a pair of oppositely-disposed outlets extending from the lower portion of said chamber, an air-suppl duct having one end portion operatively connected to said heating means and its main body portion extending upwardly therefrom within said chamber and then transversely thereof substantially the entire length thereof with its other end portion terminatin relatively short of the inner wall of that side of said chamber which is opposite said heating means, an outlet conduit disposed within said duct and being of less diameter than the same so as to provide a space therebetween, said conduit having one end portion also operatively connected to said heating means and its opposite end portion extending outwardly through said opposite side of the curing chamber, an exhaust pipe extending outwardly from said chamber independently of either said duct or conduit, and thermostatic control means for selectively controlling the passage of gases through the apparatus.

JAMES B. MOORE, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 106,205 Rice Aug. 9, 1870 1,339,374 Buensod May 4, 1920 1,670,263 Koonce et al May 15, 1928 2,071,801 Rust Feb. 23, 1937 2,095,186 Gill Oct. 5, 1937 2,212,222 Austin Aug. 20, 1940 2,296,806 Buckholdt Sept. 22, 1942 

